U.S. patent application number 12/251588 was filed with the patent office on 2009-04-23 for systems and methods for regulating purge flow rate in an internal combustion engine.
Invention is credited to Eric B. Hudak, Terrence M. Rotter, Nathan R. Vogt.
Application Number | 20090100828 12/251588 |
Document ID | / |
Family ID | 40562074 |
Filed Date | 2009-04-23 |
United States Patent
Application |
20090100828 |
Kind Code |
A1 |
Hudak; Eric B. ; et
al. |
April 23, 2009 |
Systems and Methods for Regulating Purge Flow Rate in an Internal
Combustion Engine
Abstract
A system and method of controlling/adjusting purge flow rate in
an internal combustion engine is disclosed. The system includes an
air intake assembly, a fuel tank assembly and an evaporative
emissions control device such as a carbon canister in operational
association with each other. Fuel vapors from the fuel tank
assembly flow into the evaporative emissions control device for
adsorption. The adsorbed fuel vapors from the evaporative emissions
control device are recovered, at least in part due to pressure
differentials, and actively purged into the internal combustion
engine. The purge flow rate from the evaporative emissions control
device is controlled/adjusted by a flow control device, the flow
control device that is at least indirectly connected to the
evaporative emissions control device and the air intake assembly.
In one aspect, the flow control device can comprise an orifice
device, such as, a connector device having at least one orifice for
regulating purge flow rate. In another aspect, the flow control
device can comprise a filter device for cleaning the intake and/or
purged air in addition to regulating the purge flow rate.
Inventors: |
Hudak; Eric B.; (Sheboygan,
WI) ; Rotter; Terrence M.; (Sheboygan Falls, WI)
; Vogt; Nathan R.; (Elkhart Lake, WI) |
Correspondence
Address: |
WHYTE HIRSCHBOECK DUDEK S C;INTELLECTUAL PROPERTY DEPARTMENT
555 EAST WELLS STREET, SUITE 1900
MILWAUKEE
WI
53202
US
|
Family ID: |
40562074 |
Appl. No.: |
12/251588 |
Filed: |
October 15, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60980658 |
Oct 17, 2007 |
|
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|
Current U.S.
Class: |
60/324 |
Current CPC
Class: |
F02M 25/0872 20130101;
F02M 25/0836 20130101 |
Class at
Publication: |
60/324 |
International
Class: |
F01N 7/00 20060101
F01N007/00 |
Claims
1) An evaporative emissions system for regulating a purge flow rate
in an internal combustion engine, the system comprising: an air
intake assembly for providing a mixture of intake air and fuel to
the internal combustion engine; an evaporative emissions control
device for purging fuel vapors, the evaporative emissions control
device in fluid communication with the air intake assembly; a fuel
tank assembly for providing fuel to the air intake assembly, the
fuel tank assembly in fluid communication with (i) the evaporative
emissions control device and (ii) the air intake assembly; and a
flow control device for regulating a purge flow rate of the
evaporative emissions control device, the flow control device being
at least indirectly connected to the evaporative emissions control
device and the air intake assembly; wherein the flow control device
includes at least one of an orifice and a passageway that is sized
in relation to at least one of the evaporative emissions control
device and the fuel tank assembly; and wherein the orifice or the
passageway remains open during regulating of the purge flow
rate.
2) The system of claim 1, wherein the flow control device includes
a connector device, the connector device having a channel
terminating in an orifice and communicating at least indirectly
with the evaporative emissions control device and the air intake
assembly for regulating the purge flow rate, the connector device
not including any valve or a valve-like mechanism.
3) The system of claim 1, wherein the flow control device includes
a filter device having a plurality of air passages for regulating
the purge flow rate by varying the size of the plurality of air
passages, the filter device not including a valve or a valve-like
mechanism.
4) The system of claim 1, wherein the air intake assembly
comprises: (i) an air filter for receiving intake air from the
outside atmosphere, (ii) a carburetor located downstream of the air
filter and coupled at least indirectly to the air filter, the
carburetor being capable of mixing air and fuel together to produce
an air-fuel mixture, and (iii) an intake manifold located
downstream of the carburetor and coupled at least indirectly to the
carburetor, the intake manifold capable of transporting the
air-fuel mixture to the engine.
5) The system of claim 1, wherein the evaporative emissions control
device includes a carbon canister, the carbon canister including a
housing for receiving fuel vapors, the housing further having (i)
an inner chamber containing an adsorbent material capable of
adsorbing fuel vapors and (ii) a plurality of ports including: (a)
a first port for communicating with the fuel tank assembly for
receiving fuel vapors therefrom; (b) a second port for
communicating with the outside atmosphere for purging the fuel
vapors received via the first port; and (c) a third port for
communicating with the air intake assembly for transporting the
purged fuel vapors thereto.
6) The system of claim 1, wherein a single evaporative emissions
control device is used for purging fuel vapors in conjunction with
the flow control device.
7) The system of claim 1, wherein the fuel tank assembly includes a
housing having an inner chamber capable of containing a liquid
fuel, the housing further providing for an air space above the
upper surface of the liquid fuel when the housing contains the
fuel, the air space for collecting liquid fuel vapors, wherein the
housing can further include a vent having a vent opening for
transferring fuel vapors from the fuel tank assembly to the
evaporative emissions control device.
8) The system of claim 1, wherein the fluid communication between
the air intake assembly, the evaporative emissions control device
and the fuel tank assembly includes at least one of (i) a vapor
line or conduit connecting the fuel tank assembly and the
evaporative emissions control device; (ii) a fuel line or conduit
connecting the fuel tank assembly and the air intake assembly; and
(iii) a purge line or conduit connecting the evaporative emissions
control device and the air intake assembly.
9) A connector device comprising: a channel section, the channel
section having at least one channel terminating in at least one
orifice, the orifice for regulating an evaporative emission purge
flow rate in an internal combustion engine, wherein the orifice
remains open when regulating the purge flow rate.
10) The connector device of claim 9, wherein the channel section
further includes a first portion and a second portion, each of the
first and the second portions having at least one orifice such that
fuel vapors enter the connector device through the at least one
orifice of the first portion and exit through the at least one
orifice of the second portion for regulating the purge flow rate
into the internal combustion engine.
11) The connector device of claim 9, further comprising a
frusto-conical portion and a cylindrical portion, at least one of
the frusto-conical and cylindrical portions having the at least one
orifice for receiving fuel vapors.
12) The connector device of claim 9, further comprising a support
section connected at least indirectly to the channel section, the
support section further comprising: a first portion and a second
portion, the first and second portions being connected by a support
section support member; and a connector portion for connecting the
channel section to the support section.
13) The connector device of claim 12, wherein the first and the
second portions and the connector portion of the support section
include at least one of the following: (i) the first portion of the
support section including either an anchor or a flat-arrow shape;
(ii) the second portion of the support section including an arched
member for providing support to the channel section; and (iii) the
connector portion having a cylindrical portion at least partially
surrounding the channel section and a tubular portion extending
from the cylindrical portion, the tubular portion in mating
alignment with the support section.
14) The connector device of claim 9, wherein regulating the purge
flow rate is accomplished without using a valve or a valve-like
mechanism.
15) A method of regulating purge flow rate associated with
evaporative emissions in an internal combustion engine, the method
comprising, providing an air intake assembly, a fuel tank assembly,
and an evaporative emissions control device in operational
association with each other, as well as a flow control device that
is connected at least indirectly to the evaporative emissions
control device and the air intake assembly, the flow control device
including at least one of an orifice and a passageway, the least
one orifice and passageway sized in relation to at least one of the
evaporative emissions control device and the fuel tank assembly;
receiving fuel vapors at least indirectly from the fuel tank
assembly and into the evaporative emissions control device; and
purging the fuel vapors from the evaporative emissions control
device using the flow control device so as to regulate the purge
flow rate into the internal combustion engine; wherein the at least
one orifice and passageway remains open during regulating the purge
flow rate.
16) The method of claim 15, wherein the purging of the fuel vapors
further comprises: adsorbing the fuel vapors into an adsorbent
media located within the evaporative emissions control device; and
recovering the adsorbed fuel vapors from the adsorbent media by
receiving air from exterior of the evaporative emissions control
device into the inside of the evaporative emissions control
device.
17) The method of claim 15, wherein providing the flow control
device connected at least indirectly to the evaporative emissions
control device and the air intake assembly further comprises
providing a connector device having at least one orifice, and
locating the connector device in at least one of the following: (a)
adjacent the evaporative emissions control device; (b) adjacent a
carburetor of the air intake assembly; (c) adjacent to an intake
manifold of the air intake assembly; (d) adjacent an air filter of
the air intake assembly; and (e) intermediate or substantially
intermediate between the evaporative emissions control device and
the carburetor.
18) The method of claim 15, wherein providing the flow control
device connected at least indirectly to the evaporative emissions
control device and the air intake assembly further comprises
providing a filter device, the filter device having a plurality of
air passages, such that the size of the plurality of air passages
can be varied for (i) regulating the purge flow rate; and (ii)
cleaning the purged fuel vapors and outside air received via the
air intake assembly; and further providing the filter device having
the plurality of air passages in at least one of the following: (a)
adjacent the evaporative emissions control device; (b) adjacent a
carburetor of the air intake assembly; (c) adjacent to an intake
manifold of the air intake assembly; (d) adjacent an air filter of
the air intake assembly and (e) intermediate or substantially
intermediate between the evaporative emissions control device and
the carburetor.
19) The method of claim 15, wherein the purge flow rate can be
regulated without requiring re-calibration of a carburetor in an
internal combustion engine.
20) The method of claim 15, wherein regulating of the purge flow
rate is accomplished without using a valve or a valve-like
mechanism.
21) An engine in combination with an evaporative emissions system,
the combination comprising: an engine; and an evaporative emissions
system comprising: an air intake assembly, a fuel tank assembly and
an evaporative emissions control device in operational association
with one another, and a flow control device connected at least
indirectly to the evaporative emissions control device and the air
intake assembly, the flow control device for regulating a purge
flow rate into the engine, the flow control device including at
least one of an orifice and a passageway that is sized in relation
to at least one of the evaporative emissions control device and the
fuel tank assembly.
22) The combination of claim 21, wherein the engine is an internal
combustion engine, and wherein the flow control device is selected
from at least one of a connector device and a filter device.
23) A method of using a sintered metal filter for purging and
cleaning evaporative emissions in an internal combustion engine,
the method comprising: providing a sintered metal filter having a
plurality of passageways formed therein; using the plurality of
passageways to regulate the purge flow rate and to clean purged
evaporative emissions; wherein the plurality of passageways remain
open during the purging of the evaporative emissions.
24) The method of claim 23, wherein the at least one of the
plurality of passageways is sized in relation to at least one of an
evaporative emissions control device and a fuel tank assembly of
the internal combustion engine so as to regulate the purge flow
rate.
25) The method of claim 23, wherein the providing of the sintered
metal filter does not include providing a valve or a valve-like
mechanism for use in or in conjunction with the filter.
26) The evaporative emissions system of claim 1, wherein the flow
control device is positioned intermediate or substantially
intermediate between the air intake assembly and the evaporative
emissions control device.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional
patent application No. 60/980,658 entitled "systems and methods for
regulating purge flow rate in an internal combustion engine" filed
on Oct. 17, 2007, which is hereby incorporated by reference
herein.
FIELD OF THE INVENTION
[0002] The present invention relates to internal combustion engines
and, more particularly, to evaporative emissions control systems
and methods employed in internal combustion engines.
BACKGROUND OF THE INVENTION
[0003] Small internal combustion engines are used in a wide variety
of applications including for example, lawn mowers, lawn tractors,
snow blowers and power machinery. It is common to find that such
internal combustion engines employ a carburetor to provide an
appropriate air/fuel mixture (also called "charge") to the
combustion chamber of the internal combustion chamber. Frequently,
carburetors of such internal combustion engines are connected via a
supply line to a fuel tank that store fuels such as gasoline,
diesel fuel and other types of liquid fuels used by the engines.
Typically, fuel enters the carburetor from the fuel tank at least
in part due to pressure differentials between the fuel tank and the
venturi region of the carburetor. The fuel is mixed with air within
the venturi region of the carburetor.
[0004] When situated within a fuel tank, certain amounts of a
liquid fuel typically become vaporized as hydrocarbons,
particularly when temperatures within the tank rises, when the
tanks experience high levels of jostling, and/or when the volume
within the tank unoccupied by fuel (and filled with air) becomes
rather large relative to the air space. The vaporization of fuel
continues even during the normal course of storage of the fuel
within the fuel tank.
[0005] Fuel vapors emanating from the fuel tanks of internal
combustion engines are a main contributor to evaporative emissions
from such engines. Such emissions from fuel tanks can occur
particularly when passage(s) are formed that link the interior of
the fuel tank with the outside atmosphere, for example, for venting
purposes as well as when refueling occurs. Because fuel vapors can
contribute to ozone and urban smog and otherwise negatively impact
the environment, increasingly it is desired that these evaporative
emissions from fuel tanks be entirely eliminated or at least
reduced. In particular, legislation has recently been enacted (or
is in the process of being enacted) in various jurisdictions such
as California placing restrictions on the evaporative emissions of
Small Off Road Engines (SORE), such as those employed in various
small off-road vehicles and other small vehicles that are used to
perform various functions in relation to the environment, for
example, lawn mowers and snow blowers.
[0006] For at least these reasons, therefore, it would be
advantageous if an improved system/device and/or method could be
created to prevent or reduce evaporative emissions from fuel tanks,
such as the fuel tanks of internal combustion engines including,
for example, SORE engines.
BRIEF SUMMARY OF THE INVENTION
[0007] In one aspect, the present invention relates to an
evaporative emissions system for adjusting and/or controlling the
purge flow rate of evaporative fuel vapors from a carbon canister
in an internal combustion engine. The system includes an air intake
assembly comprising an air filter, carburetor and an intake
manifold in operational association with each other. The system
also includes an evaporative emissions control device that is in
fluid communication with the air intake assembly. The system
further includes a fuel tank assembly in fluid communication with
both, the evaporative emissions control device and the air intake
assembly, and a housing that is capable of storing liquid fuels as
well as an air space above the upper surface of the liquid fuel.
The liquid fuel stored within the housing is additionally capable
of evaporation producing fuel vapors comprising volatile organic
compounds (VOC), which collect in the air space above the liquid
fuel. The fuel vapors from the housing flow into the evaporative
emissions control device and are subsequently purged into the
internal combustion engine. In one embodiment, the purge rate of
the fuel vapors can be regulated by a flow control device connected
at least indirectly to the evaporative emissions control device and
the air intake assembly. The flow control device further includes
at least one of an orifice and a passageway, at least one of the
orifice and the passageway sized in relation to the evaporative
emissions control device and the fuel tank assembly.
[0008] In another aspect, a method for regulating purge flow rate
into an internal combustion engine is disclosed. The method
comprises providing an air intake assembly, an evaporative
emissions control device and a fuel tank assembly in operational
association with each other. A flow control device connected at
least indirectly to the evaporative emissions control device and
the air intake assembly is also provided. The method for regulating
the purge flow rate can further comprise receiving fuel vapors at
least indirectly from the fuel tank assembly into the evaporative
emissions control device and purging the received fuel vapors into
the internal combustion engine using the flow control device.
[0009] And in another aspect, the flow control device can comprise
an orifice device, and more specifically, a connector device,
having a channel section having a channel for receiving fuel
vapors. Additionally, the channel terminates in at least one
orifice to regulate purge flow rate.
[0010] In yet another aspect, the flow control device can comprise
a filter device connected at least indirectly to the evaporative
emissions control device and the air intake assembly. The filter
device is used for cleaning the intake and/or purged air in
addition to regulating the purge flow rate.
[0011] Other aspects and embodiments are contemplated and
considered within the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Embodiments of the invention are disclosed with reference to
the accompanying drawings and these embodiments are provided for
illustrative purposes only. The invention is not limited in its
application to the details of construction or the arrangement of
the components illustrated in the drawings. Rather, the invention
is capable of other embodiments and/or of being practiced or
carried out in other various ways. The drawings illustrate a best
mode presently contemplated for carrying out the invention. Like
reference numerals are used to indicate like components. In the
drawings:
[0013] FIG. 1A is a front view of an evaporative emissions control
system utilizing a flow control device in accordance with at least
some embodiments of the present invention;
[0014] FIG. 1B is a top plan view of the system of FIG. 1A;
[0015] FIG. 2 is a side perspective view of a first embodiment of
the flow control device, which when used in conjunction with, for
example, the system of FIG. 1A, is capable of controlling the purge
flow rate of evaporative emissions, in accordance with at least
some embodiments of the present invention;
[0016] FIG. 3 is a graphical representation of the effect of
connector orifice size on purge flow rate;
[0017] FIGS. 4A-D are schematic illustrations of various exemplary
placement locations of the flow control device when positioned
and/or used in conjunction with the system of FIG. 1A, in
accordance with at least some embodiments of the present
invention.
[0018] FIG. 5A is a front view of an evaporative emissions control
system employing a second embodiment of the flow control device for
controlling the purge flow rate of evaporative emissions, in
accordance with at least some alternate embodiments of the present
invention; and
[0019] FIG. 5B is a schematic illustration of various exemplary
placement locations of the flow control device of when positioned
and/or used in conjunction with the system of FIG. 5A, in
accordance with at least some embodiments of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Referring to FIGS. 1A and 1B, front and top views,
respectively, of an evaporative emissions control system, generally
referenced by the numeral 2, are shown in accordance with at least
some embodiments of the present invention. The evaporative
emissions control system 2 is contemplated for use in, as part of,
or in conjunction or combination with an engine 3. In particular,
the engine 3 can be any of a wide variety of engines. For example,
some embodiments of the present invention can be employed in
conjunction with SORE engines including Class 1 and Class 2 small
off-road engines such as those implemented in various machinery and
vehicles, including, for example, lawn movers, air compressors, and
the like. Indeed, in at least some such embodiments, the present
invention is intended to be applicable to "non-road engines" as
defined in 40 C.F.R. .sctn.90.3, which states in pertinent part as
follows: "Non-road engine means . . . any internal combustion
engine: (i) in or on a piece of equipment that is self-propelled or
serves a dual purpose by both propelling itself and performing
another function (such as garden tractors, off-highway mobile
cranes, and bulldozers); or (ii) in or on a piece of equipment that
is intended to be propelled while performing its function (such as
lawnmowers and string trimmers); or (iii) that, by itself or in or
on a piece of equipment, is portable or transportable, meaning
designed to be and capable of being carried or moved from one
location to another. Indicia of transportability include, but are
not limited to, wheels, skids, carrying handles, dolly, trailer, or
platform."
[0021] Additionally, the evaporative emissions control system 2
includes an air intake assembly 4, a fuel tank assembly 6 and an
evaporative emissions control device 8, each in operational
association with one another. The air intake assembly 4 and the
fuel tank assembly 6 are in fluid communication with the
evaporative emissions control device 8 via a purge line 10 and a
vapor line 12, respectively. The air intake assembly 4 conveys air
from the outside atmosphere to the combustion chamber (not shown)
of the engine for expansion and ignition. As air travels through
the air intake assembly 4, air and fuel are mixed together to
produce an air/fuel mixture, also called charge, which is delivered
to the combustion chamber.
[0022] With reference still to FIGS. 1A and 1B, the air intake
assembly 4 includes an air filter 14, a carburetor 16 and an intake
manifold 18. Air from the outside enters the air intake assembly 4
through the air filter 14. While the various components of the air
filter 14 are not shown in detail in FIGS. 1A and 1B, a typical air
filter of the kind that can be used with the present invention as
illustrated includes a filter housing (not shown) having air inlet
and outlet ends. Air typically enters the filter housing via the
air inlet ends and passes through a filtering media located within
an inner chamber of the filter housing. By virtue of the air
passing through the filtering media, dust, debris, dirt and other
particles are filtered from the air resulting in clean, or
substantially clean, air that passes into the carburetor 16 through
the outlet ends of the air filter 14. An optional evaporative valve
can be present downstream of the air filter 14 in alternate
embodiments for preventing fuel vapors from the carburetor 16 from
being vented to the outside atmosphere through the air filter 14
when the engine is not in operation.
[0023] Although all the internal components of the carburetor 16
are not shown in FIGS. 1A and 1B, a typical carburetor of the kind
that can be used in the present invention as illustrated includes
at least the following components described below. The carburetor
16 is typically located downstream of the air filter 14 and is at
least indirectly coupled to the air filter for receiving intake air
from the air filter. Clean air from the air filter 14 enters the
carburetor 16 and is transported into a narrow throat region for
combining with fuel to produce charge for delivery to the
combustion chamber. The throat region of the carburetor 16 in
particular, includes a narrow, constricted venturi region for
mixing air and fuel together. Fuel is drawn into the venturi region
through a fuel nozzle connected to the fuel tank assembly 6, as
discussed in more detail below. The fuel nozzle is generally
located proximate to the throat region and fuel enters the venturi
region due to pressure differentials arising from the venturi
action within the venturi region as air passes through the region
during running of the engine.
[0024] Disposed additionally downstream of the venturi region is a
throttle value configured to control the flow of charge through the
carburetor. The charge exiting the carburetor 16 enters the intake
manifold 18 in a manner well known in the art. The intake manifold
18 then communicates the charge for ignition to the combustion
chamber of the engine located downstream of the intake manifold
(not shown).
[0025] The fuel tank assembly 6 includes a fuel tank 20 having a
housing 21 and an input port 22. The shape and size of the fuel
tank 20, as well as the material from which the housing 21 is
constructed, can vary to convenience depending upon a number of
factors, including: a) the internal combustion engine with which
the fuel tank housing is used, b) the particular application for
the engine, and c) the type of fuel that is stored or housed within
the fuel tank housing. Typically, liquid fuel that is capable of
evaporation at normal temperatures and pressures, such as gasoline,
is stored within the fuel tank 20. In accordance with various
embodiments of the invention, the fuel from the fuel tank 20 flows
towards the carburetor 16 through an output port 24 via a fuel line
26. The fuel line 26 is coupled to the carburetor 16, typically to
a fuel nozzle within the carburetor throat region (not shown). As a
result, fuel is drawn into the venturi region from the fuel tank 20
through the fuel line 26. A fuel shut-off valve 25 can be present
at the junction of the output port 24 and the fuel line 26. By
virtue of the device (e.g., a fuel shut-off valve), the flow of
fuel from the fuel tank 20 can be controlled. Optionally, a fuel
filter 28 can be attached to the fuel line 26 for filtering dust
and debris from the liquid fuel.
[0026] With reference still to FIGS. 1A and 1B, the input port 22
of the fuel tank 20 is sealably engaged by a fuel tank cap 30,
which allows for opening or closing the fuel tank. Typically, the
fuel tank cap 30 is a removable cap having internal threads that
engage with the external threads of the input port 22. It should be
understood that the fuel tank cap 30 provided is only exemplary and
variations and alternatives are considered within the scope of the
invention. For example, in some applications, the cap threads (not
shown) can be external as opposed to internal. Additional sealing
in the form of gaskets can be provided between the fuel tank cap 30
and the input port 22 such that atmospheric air from the outside
cannot enter the fuel tank 20 and fuel vapors on the inside are
prevented from being vented to the outside. Fuel vapors comprising
of hydrocarbons (i.e., vaporized fuel and residual gases) collect
in an air space above the upper surface of the liquid fuel due to a
wide variety of reasons including, for example, fuel evaporation at
high temperatures and jostling of the fuel tank 20 during operation
of the engine. Such collected fuel vapors are eventually vented to
the outside as the fuel cap is opened (for e.g., for re-fuelling)
leading to undesirable evaporative emissions and fuel waste.
[0027] To minimize or possibly even completely eliminate the fuel
vapors from being vented to the outside, the fuel tank 20 has
formed thereon, or otherwise includes, a vent opening 32 (See FIG.
1B) adjacent to the input port 22. The vent opening 32 is coupled
to one end of the vapor line 12, and conveys fuel vapors from
within the fuel tank 20 to the evaporative emissions control device
8. By virtue of the vent opening 32 being connected to the vapor
line 12 and fuel vapors flowing into the evaporative emissions
control device 8 through the vapor line, fuel vapors are trapped or
otherwise contained within the evaporative emissions control
device. In this fashion, evaporative emissions are controlled (this
is explained in more detail below). The vent opening 32 can
optionally be equipped with a roll-over valve 33 (See FIG. 1B), or
other suitable mechanism, positioned over the vent opening and the
valve or other mechanism prevents the liquid fuel within the fuel
tank 20 from flowing through the vapor line 10 and into the
evaporative emissions control device 8.
[0028] The evaporative emissions control device 8 of the present
embodiment is typically a conventional canister or canister-type
device (e.g., a carbon canister) that is in fluid communication
with the air intake assembly 4 and the fuel tank assembly 6 and is
also linked to the outside atmosphere. The evaporative emissions
control device 8 in particular can be a separate stand-alone
component coupled to the air filter 14, the carburetor 16, the
intake manifold 18, or any other suitable component of the internal
combustion engine. Alternatively, it is contemplated that the
device 8 may be integrated into any of these or other components.
The functionality of the evaporative emissions control device 8 is
at least two-fold. First, the evaporative emissions control device
8 traps fuel vapors (i.e., containing a vaporized fuel component
and the residual gases) from the fuel tank 20 to reduce evaporative
emissions and purges those fuel vapors into the engine when the
engine is running. Alternatively, when the engine is not running,
the evaporative emissions control device 8 serves to trap the fuel
vapors and recover the trapped fuel component from the fuel vapors
for actively purging the recovered fuel into the engine and
expelling any residual gases (e.g., air or fresh air) into the
atmosphere. By virtue of the purging action of the evaporative
emissions control device 8, as well as the expulsion of the
residual gases (when the engine is not running), undesirable
evaporative emissions, as well as fuel wastage, are both
reduced.
[0029] For trapping and purging purposes, the evaporative emissions
control device 8 includes a canister housing 34. The housing
typically includes a chamber with a wall extending at least
partially therein, and the wall provides a U-shaped cross-section
of the chamber or interior of the canister housing. A plurality of
ports (see FIG. 1B), including a fuel tank port 36, a purge port 38
and a fresh air port (not shown), are typically are formed on, or
are otherwise provided by, the canister housing 34. In the present
embodiment, all these ports are located on one side or one end of
the canister housing 34 (as can be seen in FIG. 1B). However, it
shall be understood that the exact location and/or orientation of
the various ports can vary to convenience depending, for example,
upon the location of the evaporative emissions control device 8
within the internal combustion engine or its location with respect
to other system components or assemblies. In particular, the fresh
air port is used for transporting fresh air from the outside to the
inside for assisting in the purging action. The fresh air port is
additionally employed for expelling any residual gases (e.g., gases
without any or substantially any fuel component) into the
atmosphere when the engine is not running. The purge port 38
connects the evaporative emissions control device 8 to the air
intake assembly 4 for actively purging the fuel vapors into the
engine. In other words, when the engine is running, the fuel
vapors, including the air (or fresh air) are ingested into the
engine. When the engine is not running, the fuel vapors are
captured in the evaporative emissions control device 8 and the
residual gasses (e.g., air without the fuel component of the fuel
vapors) get expelled through the fresh air port to the atmosphere.
The fuel port 36 receives fuel vapors containing hydrocarbons from
the fuel tank 20 for adsorption.
[0030] Adsorption of the fuel vapors within the evaporative
emissions control device 8 is performed by way of an adsorbent
media, such as, by way of example and not limitation, activated
charcoal, or carbon pellets, located within the canister housing
34. Although, charcoal is a frequently used adsorbent media, other
adsorbent media that are commonly available can potentially be
used. The charcoal adsorbent material within the carbon canister is
generally rated by its Normal Butane Capacity (NBC) measured in
grams/milliliter. A typical NBC rating for such a media is 10
although carbon having other ratings is commercially available and
can be used. In one embodiment, the evaporative emissions control
device 8 includes only a single variety of the adsorbent material
having a single evaporated adsorption fuel level (for e.g., the NBC
rating). Nevertheless, in other embodiments, one or more additional
or other types of adsorbent materials, each having different
evaporated adsorption fuel levels, can be used.
[0031] One way of controlling evaporative emissions for SORE
engines is by utilizing carbon canisters (of the kind described
above) to trap the vented hydrocarbons from the fuel tank 20. The
evaporative emissions control device sizes are typically determined
based upon the volumetric capacity of the fuel tank 20 of the
internal combustion engine. For example, a typical ratio of the
quantity of liquid fuel within the fuel tank 20 to the adsorbent
material within the canister housing 34 is 1.4 grams of hydrocarbon
working capacity per liter of the size of the fuel tank 20 (1.4 g
HC W.C./L fuel tank). However, the foregoing can be varied
depending upon the NBC rating of the carbon used within the
adsorbent media of the evaporative emissions control device 8.
Generally, an internal combustion engine model can be used for a
wide variety of applications requiring a variety of fuel tank sizes
thereby resulting in a wide variety of designs and sizes of the
evaporative emissions control device 8, all for achieving optimum
purge flow rates.
[0032] Due to the various sizes and designs of the carbon
canisters, the purge rate and concentration of hydrocarbons in the
purge air can vary, resulting in varying engine performances. To
prevent the engine performance from changing due to change in
carbon canisters, it is often required that the carburetor be
re-calibrated. Re-calibration of the carburetor can be an
inconvenient, time consuming and a costly operation.
Advantageously, the present invention provides flow control devices
(discussed below) that are capable of controlling the purge flow
rate without the requirement of re-calibrating the carburetor to
obtain optimum engine performance, even while including varying
carbon canisters (e.g., canisters of different sizes and
designs).
[0033] Referring now to FIG. 2, a first embodiment of a flow
control device 40 is shown in accordance with at least some
embodiments of the present invention. Further, in at least some
preferred embodiments of the present invention, the first
embodiment of the flow control device 40 is an orifice connector 41
used in conjunction with the evaporative emissions control system
2, as shown from a side perspective view in FIG. 2. More generally,
the orifice connector can be referred to as, or termed, an "orifice
device". Using the flow control device 40 of the kind shown (e.g.,
the orifice connector 41) connected at least indirectly to the
evaporative emissions control device 8 and the air intake assembly
4, the purge flow rate can be regulated (explained in greater
detail below). The orifice connector 41 is typically placed on the
purge line 10, although the location of the orifice connector 41 on
the purge line can vary. In general, the first embodiment of the
flow control device 40 employing the exemplary orifice connector 41
includes an orifice, sized so as to regulate the purge flow rate,
as will be described in greater detail below.
[0034] The flow control device 40, and more specifically the
orifice connector 41 shown, can typically be connected to the purge
line 10 in a variety of ways. For example, the orifice connecter 41
can be connected by severing or otherwise disconnecting a small
section of the purge line and connecting the orifice connector to
the disconnected ends of the purge line. Alternatively, the
respective line (e.g., the purge line) can be provided in a
plurality (e.g., two) of portions and the portions connected
together using the orifice connector. Various other connecting and
engaging options and/or methods are contemplated and considered
within the scope of the present invention. As shown, the orifice
connecter 41 is a T-shaped (or substantially T-shaped) structure
having first and second sections 42 and 44, respectively, connected
together by way of a connection flange or flange-like section or a
support section support member 43. Typically, the orifice connector
41 is made of molded plastic although other flexible or rigid
materials or potentially even metals can be used. Additionally, the
respective first and second sections 42 and 44 and the connection
flange 43 may be formed as separate pieces coupled together in
operational association or possibly as a unitary molded piece.
[0035] In general, the first section 42 of the orifice connector 41
includes a hollow cylindrical tube portion (or a channel section)
46 having first and second portions 45 and 47. In the present
embodiment, the cylindrical tube 46 has smooth walls along its
length and uniform dimensions. Further as shown in the present
embodiment, portion 45 includes a barbed or barb-shaped portion 48,
which serves as a receiving port for the fuel vapors coming from
the evaporative emissions control device 8. Portion 47 has a
regular circular contour and serves as an exit port for the fuel
vapors flowing through the orifice connector 41 and headed towards
the air intake assembly 4. It is contemplated that, in other
embodiments, both portions 45 and 47 can potentially be extended to
form barbed shaped portions.
[0036] Still referring to FIG. 2, the orifice connector 41 is
typically placed along, or connected to, the purge line 10 (as
shown in FIG. 1A) such that the barbed portion 48 provides a tight
seal between the purge line and the orifice connector. Insofar as a
tight seal between the purge line 10 and the orifice connector 41
is provided, fuel vapors can be prevented from escaping into the
outside atmosphere during the purging action. The barbed shaped
portion 48 is normally capped during shipping to prevent damage, as
well as entry of undesirable particles or materials into the
orifice connector 41 which might ultimately cause issues when the
connecter is placed into use (e.g., blocking or obstructing the
passage of the fuel vapors). Similar caps or covers can be present
at the second portion 47 as well.
[0037] The barbed or barb-shaped portion 48 further includes a
frusto-conical portion 49 adjacent to the first portion 45 and a
cylindrical portion 51 having an orifice 50 and extending from the
frusto-conical portion. Fuel vapors from the evaporative emissions
control device 8 enter the orifice connector 41 through the orifice
50 and exit through the second portion 47. The orifice 50 is in
fluid communication with a channel or hollow portion (hidden from
view) of the cylindrical tube 46. As such, a clear and unobstructed
passage for air flow from the barbed shaped portion 48 of the first
portion 45 to the second portion 47 through the orifice of the
cylindrical tube is formed. The orifice 50 is typically placed
directly in-line with the purge line 10 to prevent any loss as fuel
vapors travel from the evaporative emissions control device 8 to
the air intake assembly 4.
[0038] Additionally, the orifice 50 remains open at all times for
regulating the purge flow rate of the evaporative emissions control
device 8. Insofar as the orifice 50 remains open at all times, the
orifice 50 does not employ a valve or a valve-like mechanism, which
is capable of being opened and/or closed depending upon various
conditions of the system within which the valve or the valve-like
mechanism is employed. Furthermore, depending upon the size of the
orifice 50, the amount of fuel vapors entering the orifice
connector 41 can vary and be controlled. Therefore, by virtue of
varying the orifice sizes as the sizes of the fuel tank 20 change,
desired purge flow rates can be achieved. The variance of the purge
flow rates with varying orifice sizes is shown in FIG. 3, described
in more detail below. In particular, to achieve a desired purge
flow rate, an orifice connector having an appropriately sized
orifice can be connected to the purge line 10.
[0039] Still referring to FIG. 2, the second section (or the
support section) 44 of the orifice connector 41 provides a support
feature having an anchor-shaped portion 54 (having a flat
arrow-like shape) and an arched member 56. In at least some
embodiments of the present invention, the support feature of the
second section 44 can be termed as a "rosebud" feature. In
particular, the second section 44 permits the orifice connector 41
to semi-permanently attach to the purge line 10 while providing
additional support to the orifice connector. The connection flange
43 provides support to the cylindrical tube 46 (especially to
cylindrical tubes made of a flexible material) avoiding any bending
that may result over time in course of the regular operation of the
orifice connector 41. The connection flange 43 is a T-shaped
structure having a broader cylindrical portion 64 surrounding the
cylindrical tube 46 and a narrower tubular portion 66 that extends
downwards from the broader portion to mate with the second section
44 through the arched member 56. The broader portion 64 provides
support to the cylindrical tube 46 and further serves as a handle
for holding the orifice connector 41. Generally, it should be
understood that the other contours and/or shapes for the connector
are contemplated and considered within the scope of the present
invention.
[0040] Referring now to FIG. 3 in conjunction with FIG. 2, a
graphical representation of the effect of orifice size of the
orifice connector 41, which again is an exemplary orifice device
provided in accordance with the first embodiment of the flow
control device 40, on the purge rate of the fuel vapors is shown
for different engine models. Shown are three different engine
models, namely, first, second and third engines 68, 70 and 72
exemplifying engines SV720, SV610 and CH740, all of which are
available from the Kohler Company of Kohler, Wis. As shown, as the
orifice size (on the X-axis) is increased for a particular engine
model, the amount of hydrocarbons purged (on the Y-axis) from the
canister into the engine is also increased. For example, as the
orifice size is increased from 0.050 inches to 0.060 inches for the
first engine 68, the purge rate of the engine goes up from
approximately 17 grams to 37 grams providing approximately a 118%
increase with 0.010 inches increase in the orifice size. Similarly,
for second and third engines 70 and 72 respectively, increase of
the orifice size from 0.060 inches to 0.080 inches increases the
purge rate of the second engine from approximately 21 grams to 34
grams while the third engine 72 experiences an increase in purge
rate from 22 grams to 31 grams, an approximate increase of 62% and
41% respectively.
[0041] Therefore, increase in the purging rate of the hydrocarbons
with the increase in the orifice size effectively illustrates that
the orifice connector 41 can be used to "calibrate" the purge rate
of the evaporative emissions control device 8 into the engine. It
is noted again that the orifice connector 41 is an exemplary
orifice device provided in accordance with the first embodiment of
the flow control device and in accordance with at least some
aspects of the invention. Advantageously, by virtue of the orifice
connector 41 controlling the purge flow rate of the hydrocarbons,
the only component that needs to be changed to accommodate various
shapes and sizes of evaporative emissions control devices and fuel
tanks is the orifice connector 41 itself. Therefore, the orifice
connector 41 provides an easy and cost efficient medium of
maintaining the engine performance without changing or substituting
system or engine components, such as changing or substituting
evaporative emission control devices (e.g., canisters), which can
be costly and time-consuming.
[0042] In general, the dimensions of the orifice connector 41 can
vary to convenience. In the present embodiment, the orifice
connector 41 has a length "L" that is approximately 43 mm long and
a width "W" of approximately 20 mm, although orifice connectors
having other dimensions can be used as well in other embodiments.
In at least some alternate embodiments of the present invention,
the orifice of the first embodiment of the flow control device
(e.g., the orifice connector 41) can be sized to have a diameter of
0.060 inches for an evaporative emissions control device 8 sized
for a 5 gallon fuel tank 20. In some other embodiments, the orifice
can be sized to have diameters in the range of 0.005 inches to
0.500 inches. In alternate embodiments, orifices having diameters
other than those mentioned above can be used as well.
[0043] The location of the orifice connector 41, on the purge line
10 for controlling the purge flow rates of the fuel vapors from the
evaporative emissions control device 8 during the "purging" action
can vary, thereby resulting in the orifice being positioned in
various locations. For example, as shown in FIG. 1, the flow
control device 40 can be positioned intermediate (or substantially
intermediate) between the evaporative emissions control device 8
and the carburetor 16. Other exemplary locations for the flow
control device 40 are illustrated schematically in FIGS. 4A-4D.
Referring to FIGS. 4A-4D, exemplary placement locations of the
first embodiment of the flow control device 40 (e.g., the orifice
connector/orifice device) on the purge line 10 within the
evaporative emissions control system 2 are shown in accordance with
at least some embodiments of the present invention. More
specifically, FIGS. 4A-4D show (in schematic form) the components
of the evaporative emissions control system 2 in operational
association with one other. In particular, each of the FIGS. 4A-4D
includes the air intake assembly 4, the fuel tank assembly 6, and
the evaporative emissions control device 8 (e.g., a carbon
canister). The air intake assembly 4 includes the air filter 14,
the carburetor 16 and the intake manifold 18 coupled at least
indirectly and capable of communication with each other.
Additionally, the evaporative emissions control device 8 is in
fluid communication with the air intake assembly 4 and the fuel
tank assembly 6 by way of the purge line 10 and the vapor line 12,
respectively. Connection of the connecter device to the respective
lines or line portions at a respective location can be accomplished
in a variety of ways as previously noted.
[0044] FIG. 4A shows the first embodiment of the flow control
device 40 as being placed at, or adjacent, to the evaporative
emissions control device 8 on the purge line 10. By virtue of
placing the first embodiment of the flow control device 40 at or
near the evaporative emissions control device 8, the purge flow
rate can be controlled as the fuel vapors exit the evaporative
emissions control device 8. FIG. 4B shows the first embodiment of
the flow control device 40 to be located adjacent to a purge port
on the purge line 10 of the carburetor 16. In particular, the purge
port can be any location within the carburetor 16 where the fuel
vapors coming from the evaporative emissions control device 8 can
enter the carburetor. For example, the purge port can be located at
the venturi region supplying the purged fuel component (in addition
to the fuel supplied through the fuel nozzle) to mix with the
intake air. Additionally, the purge port can be located above the
venturi region such that intake air from the air filter 14 and the
purged fuel component are mixed together as the mixture makes way
to the venturi region for mixing with additional fuel from the fuel
nozzle. Alternatively, the purge port can be located downstream of
the venturi region within the carburetor 16 for mixing with the
charge as it exits the carburetor.
[0045] Further still, as shown in FIG. 4C, the first embodiment of
the flow control device 40 can be placed at the intake manifold 18
for controlling the purge rate. The purged fuel component flows
directly into the combustion chamber along with the charge produced
in the venturi region of the carburetor 16. And as shown in FIG.
4D, the first embodiment of the flow control device 40 can be
connected to the air filter 14. More specifically, the first
embodiment of the flow control device 40 is typically connected, as
shown, adjacent to the air inlet ports in the air filter.
Notwithstanding the placement locations of the first embodiment of
the flow control device 40 described above, in at least some
embodiments of the present invention, placing the first embodiment
of the flow control device adjacent to the purge port of the
carburetor 16 and, more particularly, to the purge port located
downstream of the venturi region (e.g., near a throttle plate of
the carburetor), is preferred. Nevertheless, other placement
locations of the first embodiment of the flow control device
described above can be employed in alternate embodiments.
[0046] The evaporative emissions system 2 need not always be
employed with the first embodiment of the flow control device 40,
as described above. Rather, as shown in FIG. 5A from a front view,
an evaporative emissions control system 2' can employ a second
embodiment of the flow control device 40, in accordance with at
least some alternate embodiments of the present invention. As
shown, the flow control device 40 is a filter device, and, more
specifically, in accordance with at least some embodiments of the
present invention, a sintered filter 74. The evaporative emissions
control system 2' is intended for use in conjunction with an engine
3'. Further as shown, the evaporative emissions control system 2'
includes an air intake assembly 4', a fuel tank assembly 6' and an
evaporative emissions control device 8' connected together in
operational association. The air intake assembly 4' includes an air
filter 14', a carburetor 16', and an intake manifold 18' connected
at least indirectly to one another. Further, the air intake
assembly 4' is in fluid communication with the evaporative
emissions control device 8' via a purge line 10' and with the fuel
tank assembly 6' via a fuel line 26' and an optional fuel filter
28'. Additional components including a fuel tank 20', fuel tank
housing 21', fuel tank input and output ports 22' and 24',
respectively, fuel tank cap 30' and fuel shut-off valve 25' are
similar or substantially similar in structure and function to that
of the corresponding components 20, 21, 22, 24, 30 and 25
respectively of the evaporative emissions control system 2. In
general, with the exception of the first embodiment of flow control
device, which is not used in the evaporative emissions control
system 2', features, components and functionality of the
evaporative emissions control system 2' closely mirror the
features, components and functionality of the evaporative emissions
control system 2. Further, the communication between the various
components of the evaporative emissions control system 2' occurs in
a manner similar or substantially similar to that of the
communication between the corresponding components in the
evaporative emissions control system 2.
[0047] In contrast to the first embodiment of the flow control
device 40 used in the embodiments of FIGS. 1-4D, the embodiments of
FIGS. 5A-5B employ a second embodiment of the flow control device,
such as, the sintered filter 74, for controlling and regulating the
purge flow rate. It is noted that the sintered filter 74 is an
exemplary filter device provided in accordance with the second
embodiment of the flow control device and in accordance with at
least some aspects of the invention. The sintered filter 74 is
located on the purge line 10' and is coupled at least indirectly to
the evaporative emissions control device 8' and the air intake
assembly 4'. A type of sintered filter that can be employed in at
least some embodiments of this invention is a sintered metal
filter. Such a sintered metal filter can be manufactured by heating
and compressing metal powder. In particular, a sintered metal
filter can be produced by compressing metal powder into a shape
(e.g., a cylindrical shape, a rectangular shape, etc.) and
subsequently heating the shape in a furnace for sintering (e.g.,
welding together) the compressed metal powder. By virtue of the
sintering operation, the shape obtained by compressing the metal
powder is retained and maintained for extended periods of time.
Insofar that the compressed powder does not completely melt to form
a solid block, a plurality of small air passages (also referred to
as ports) 75 are created in the sintered shape.
[0048] Further, the size of the air passages (or ports) 75 in the
sintered shape can be varied by controlling the density of the
compressed metal powder employed for making the sintered metal
filter. Typically, as the density of the sintered filter 74
increases, the flow area through the air passages 75 decreases,
thus restricting flow and controlling the purge flow rate.
Additionally, as the cross section of the air passages 75 (e.g.,
having a cylindrical shape) in the flow direction decreases, the
flow (e.g., the purge flow rate) is restricted. The geometry (e.g.,
length) of the sintered filter 74 additionally affects the purge
flow rate, such that a longer filter typically restricts flow (and
therefore controls the purge flow rate).
[0049] In particular, the size of the air passages 75 is typically
determined in reaction to the evaporative emissions control device
8' and the fuel tank assembly 6'. A typical metal that can be used
for manufacturing the sintered metal filter of the present
embodiment is bronze, although, other metals such as stainless
steel, and non-metals such as glass, can potentially be used in
other embodiments. Although an exemplary sintered metal filter that
can be used in at least some embodiments of the present invention
has been described above, in other embodiments, a wide variety of
sintered filters that are commonly available and frequently used,
can be used in other embodiments. In addition, the shape and size
of the sintered filter 74 can vary depending upon the application,
type of engine 3' employing the sintered filter and location of the
sintered filter within the evaporative emissions control system
2'.
[0050] As indicated above, the sintered filter 74 of the type
employed in at least some embodiments of the present invention
includes a plurality of air passages 75. The air passages 75 can be
utilized for regulating the purge flow rate of the evaporative
emissions control device 8'. Additionally, the air passages 75 of
the sintered filter 74 remain open at all times during regulating
the purge flow rate of the evaporative emissions control device 8'.
In so far that the air passages 75 remain open at all times, the
sintered filter 74 does not employ a valve or a valve-like
mechanism that is capable of being opened and closed depending upon
various conditions of the system employing the valve or the
valve-like mechanism. By virtue of utilizing such a sintered filter
having a plurality of air passages open during the regulating of
the purge flow rate, various fuel tank sizes and various
evaporative emissions control devices can be accommodated by only
changing the sintered filter 74.
[0051] In addition to regulating the purge flow rate, the sintered
filter 74 can be used for cleaning the intake air and/or the purge
air. Particularly, during operation, the evaporative emissions
control system 2' receives additional air from the outside
atmosphere for purging the fuel vapors from the evaporative
emissions control device 8' into the engine. Insofar that the
purged air is routed to the air intake assembly 4' of the engine 3'
when the engine is running, the sintered filter 74 can be used for
filtering the purged air. By filtering the purged air, the sintered
filter removes any residual dust and debris that can otherwise
enter the air intake assembly 4' thereby causing clogs and
blockages, which can reduce engine performance. Therefore, in
addition to regulating the purge flow rate, the sintered metal
filter provides an additional advantage of cleaning the purged air.
Relatedly, the sintered filter 74 can clean the intake air
depending upon the placement of the sintered filter within the
evaporative emissions control system 2', as explained below.
[0052] Therefore, in accordance with at least some embodiments of
the present invention, the sintered filter 74 can be provided for
regulating the purge flow rate and cleaning the evaporative
emissions in the evaporative emissions control system 2'. By virtue
of having the sintered filter 74 having a plurality of air passages
75 formed therein by the process described above, the purged flow
rate can be regulated. Additionally, the air sintered filter 74 can
be used for cleaning the purged air.
[0053] Referring now to FIG. 5B, exemplary placement locations of
the second embodiment of the flow control device 40 (e.g., the
sintered filter 74) on the purge line 10' are shown, in accordance
with at least some embodiments of the present invention. Also shown
in schematic form in FIG. 5B, are various components of the
evaporative emissions control system 2' including, for example, the
air intake assembly 4', the evaporative emissions control device
8', and the fuel tank assembly 6', connected together in
operational association with one another. In particular, the
evaporative emissions control device 8' is in fluid communication
with the fuel tank assembly 6' by way of the vapor line 12' and
with the air intake assembly 4' by way of the purge line 10'. In
addition, the fuel tank assembly 6' is in fluid communication with
the air intake assembly 4' via the fuel line 26' and an optional
fuel filter 28'. The air intake assembly 4' further includes the
air filter 14', the carburetor 16' and the intake manifold 18'
connected at least indirectly and capable of communication with one
another.
[0054] As indicated above, the location of the second embodiment of
the flow control device 40 (e.g., the sintered filter 74 filter
device) within the evaporative emissions control system 2' for
controlling the purge flow rate of the fuel vapors from the
evaporative emissions control device 8' into the engine 3' (See
FIG. 5A) can vary. For example, as shown in FIG. 5B, the second
embodiment of the flow control device 40 (e.g., the sintered filter
74) can be placed at, or adjacent to, the air filter 14'. In
addition to placing the second embodiment of the flow control
device 40 at, or adjacent to, the air filter 14', the second
embodiment of the flow control device can also be placed in a
plurality of alternate locations, which are shown in phantom in
FIG. 5B. For example, in at least some embodiments, the second
embodiment of the flow control device 40 (e.g., the sintered filter
74) can be placed at, or adjacent to, the evaporative emissions
control device 8'. By virtue of placing the second embodiment of
the flow control device 40 near the evaporative emissions control
device 8, the purged air can be filtered and regulated as fuel
vapors exit the evaporative emissions control device. In some other
embodiments, the second embodiment of the flow control device 40
(e.g., the sintered filter 74) can be placed adjacent to a purge
part on the purge line 10' of the carburetor 16'. As previously
mentioned in relation to the first embodiment of the flow control
device 40 (e.g., the orifice connector 41), the location of the
purge port within the carburetor 14' can vary. For example, the
purge port (and hence, the second embodiment of the flow control
device) can be located at, above, or potentially below the venturi
region of the carburetor 14'. Alternatively, the second embodiment
of the flow control device 40 (as shown, the sintered filter 74)
can be placed at the intake manifold 18' for regulating the purged
flow rate. Furthermore, as shown in FIG. 5A, in at least some
embodiments, the sintered filter 74 can be positioned intermediate
(or substantially intermediate) between the carburetor 16' and the
evaporative emission control device 8'.
[0055] The operation of the evaporative emissions control systems 2
and 2' is explained below. In general, the operation of both
evaporative emissions control systems 2 and 2' employing the first
embodiment of the flow control device 40 (e.g., the orifice
connector 41) and the second embodiment of the flow control device
(e.g., the sintered filter 74), respectively, is similar or
substantially similar. For clarification purposes, the operation is
explained with respect to the evaporative emissions control system
2, with the reference numerals of the corresponding components of
the evaporative emissions control system 2' given in
parenthesis.
[0056] When the engine is not in operation fuel vapors including a
fuel component and a hydrocarbon component collected above the
liquid fuel within the fuel tank 20 (20') pass through the vapor
line 12 (12') and into the evaporative emissions control device 8
(8') at least in part due to pressure differentials. Thereafter,
fuel vapors are adsorbed in the adsorbent material. By virtue of
the fuel vapors being adsorbed and therefore trapped within the
evaporative emissions control device 8 (8'), evaporative emissions,
which in the absence of the evaporative emissions control device
would have been emitted into the atmosphere, are trapped. At any
instant when the engine is running and the internal pressure within
the evaporative emissions control device 8 (8') is higher than the
internal pressure of the intake system (also referred herein as the
air intake assembly 4) at the purge port location, the trapped fuel
vapors can be purged into the engine. The purge rate of the trapped
fuel vapors can be controlled by way of the flow control device
(e.g., the orifice connector 41 and/or the sintered filter 74).
Typically, the purging action involves drawing atmospheric air
within the evaporative emissions control device 8 (8') through the
fresh air port. The air flow facilitates the purging action of the
fuel vapors from the evaporative emissions device 8 (8') to the
engine whereby the fuel component from the fuel vapors is
recovered. Alternatively, as the fuel tank 20 (20') has cooled down
due to non-use over extended periods of time or when the engine is
not running, the pressure differentials within the evaporative
emissions control device 8 (8') and the fuel tank can cause the
fuel component to be recovered from the adsorbent material and flow
back to the fuel tank thereby reducing fuel wastage and
reducing/eliminating evaporative emissions.
[0057] Notwithstanding the above-described embodiments, the present
invention is intended to encompass a variety of other arrangements
of orifice connectors and sintered filters within the evaporative
emissions control system. For example, although the embodiments of
FIGS. 1-4D do not illustrate the use of multiple orifices, it is
nevertheless contemplated that the present invention encompasses
and includes embodiments having more than one orifice.
[0058] Additionally, the embodiments of the flow control device, as
illustrated and previously noted, are exemplary in nature.
Notwithstanding the various embodiments of the flow control device
described above in relation to the orifice device (e.g., the
orifice connector) and the filter device (e.g., the sintered
filter), respectively, in at least some other embodiments of the
present invention, the flow control device can be formed as a
plug-like or a cork-like device ("plug/cork device") having an
orifice for regulating the purge flow rate. In embodiments
employing such a plug/cork device having an orifice, the device can
be positioned or otherwise placed within the purge line for
regulating the purge flow rate. Additionally, the plug/cork device
can be positioned within the purge line at one or more locations
described above with respect to FIGS. 4A-4D. In at least some
alternate embodiments of the present invention, the flow control
device can be formed (e.g., integrally) within the purge line, for
example, by way of crimping or otherwise squashing the purge line
so as create a pinch point within the purge line that can be
utilized for regulating the purge flow rate. The size of the pinch
point, or alternatively, the size of the orifice within such a
plug/cork device, can vary to convenience depending upon the
desired purged flow rate. In general, the flow control device in
various of its embodiments can be located within various areas of
the evaporative emissions control system, including for example,
the carburetor purge port, the evaporative emissions control
device, the evaporative line, or the like.
[0059] Further, as already noted, the exact shapes and sizes of the
orifice connector, fuel tanks, evaporative emissions control device
and/or the various components of the air intake assembly can vary
with a given embodiment. Relatedly, a plurality of sintered filters
of varying shapes and sizes can be employed in the embodiments of
FIGS. 5A-5B, with the location of one or more sintered filters
varying from that described above. Further, in at least some
embodiments, a combination of orifice connectors and sintered
filters can be used for regulating the purged flow rate.
Additionally, in at least some embodiments of the present
invention, the orifice connector and the sintered filter can be
retrofitted to the purge line for regulating the purge flow rate.
Also, in at least some other embodiments of the present invention,
the evaporative emissions system can employ a single evaporative
emissions control device while other embodiments can employ
multiple evaporative emissions control devices.
[0060] The present invention relates to a variety of embodiments of
fuel tanks, evaporative emissions control devices, air intake
assemblies and flow control devices as can be employed in a variety
of applications and for a variety of purposes. For example,
embodiments of the present invention can be employed in conjunction
with a variety of different internal combustion engines used in
vehicles, or for a variety of other purposes. Embodiments of the
present invention can be particularly beneficial insofar as they
reduce or even eliminate evaporative emissions from the fuel.
[0061] Also, it is contemplated that embodiments of the present
invention are applicable to engines that have less than one liter
in displacement, or engines that both have less than one liter in
displacement and fit within the guidelines specified by the
above-mentioned regulations. In still further embodiments, the
present invention is intended to encompass other small engines,
large spark ignition (LSI) engines, and/or other larger (mid-size
or even large) engines. In additional embodiments, the present
invention is intended to be used with containers or storage tanks
other than fuel tanks holding volatile fluids, which are producers
of volatile organic compounds (VOC) or evaporative emissions. In
alternate embodiments, the present invention is contemplated for
use with Electronic Fuel Injection (EFI) systems, in which the
purged fuel vapors pass through an EFI throttle body of the
engine.
[0062] Despite any method(s) being outlined in a step-by-step
sequence, the completion of acts or steps in a particular
chronological order is not mandatory. Further, modification,
rearrangement, combination, reordering, or the like, of acts or
steps is contemplated and considered within the scope of the
description and claims.
[0063] It is specifically intended that the present invention not
be limited to the embodiments and illustrations contained herein,
but include modified forms of those embodiments including portions
of the embodiments and combinations of elements of different
embodiments as come within the scope of the following claims.
* * * * *